Method of lining tanks for electrolytic work.



No. 857,886. PATENTED JUNE 25, 1907. J. F. MILLER.

METHOD OF LINING TANKS FOR ELECTROLYTIC WORK.

APPLICATION FILED FEB. 6, 1906.

JEMz'lZer, 3n ucn l'oz JOHN F. MILLER, or TRAIL, BRITISH eoLUMBIA,CANADA.

METHOD OF LINING TANKS FOR ELECTROLYTIC WORK.

Specification of Letters Patent.

Patented June 25, 1907.

Application filed February 6, 1906. Serial No. 299,691.

To all whom it may concern:

Be it known that L'JOHN F. MILLER, a citizen of the United States,residing at Trail, British Columbia, Canada, have invented a certain newand useful Method of Lining Tanks for Elect1 lytic.\Vorl of which thefollowing is a specification, referencebeing had to the drawingaccompanying and forming part of the same.

.[n the-use of wooden tanks oreells for cojhtaining the electrolyte inthe electrolytic refining of metals considerable dilliculty has beenexperienced in fully protecting the wood from the chemical action of theelectrolyte. This is particularlythe case with so-called built up tanks,that is, tanks constructed of sections united by tie rods or bolts. Insuch tanks the joints between sections, and also at the angles of thesides, bottom, and ends, are specially liable to be the seat of injuryfrom the electrolyte, resulting in leaks as welllas contamination of theelectrolyte by the compounds produced by the action of the electrolyteon the Wood.

Asphaltum, which is unattacked by even powerfully corrosiveelectrolytes, such for example as are used in the refining of lead bythe'Betts process, described in Reissued Letters Patent of the UnitedStates No. 12,301, dated Jan. 3, 1905, has been commonly used to coatthe interior of the tanks, but even asphaltum, as heretofore applied, isnot sufiicient protection to the joints. The asphaltum must of course beapplied while in the molten state, but this is liable to result inbubbles or flows, which may permit the electrolyte or the gases producedtherein to penetrate tothe wood. I have therefore been led to devise mypresent invention, which is a method of lining electrolytic tanks, withmore particular reference to the joints between the sections composingthe same.

The nature of the invention will be more readily understood from asomewhat detailed description of the manner in which I prefer to employit.

In the annexed drawing, Figure 1 is a de-' tail sectional view showing ajoint between sections of the tank, and showing also the result of thefirst step of my method. Fig. 2 is a similar section showing the jointcompleted.

The invention is intended more particularly for built up tanks of thetype shown in my co-pending application filed of even date herewith, inwhich the joints between sections and atthe angles of the tank aregrooved. Thepreferred form of groove is shown in the annexed drawing.Therein, a and b indicate contiguous sections from a side, an end, thebottom, or partition of the tank. Each ed ge is provided with anundercut rabbet, so that when the two are placed together the resultinggroove 0 will be wider at its bottom than at its top, as shown.

The asphaltum used for the lining must of course have a melting pointsomewhat higher, say 20 or more, than the temperature at which theelectrolyte is to be used. When the asphaltum has been heated to theproper degree of fluidity it is flowed into the groove to a depth say ofabout one eighth of an inch. While this layer is still warm it isheated, in the groove, in any suitable way, as by passing over it theflame of a gasolene lamp or paint breamer. This heating is kept up untilthe layer is so liquid that all bubbles or other flows will beeradicated and the asphaltum thus rendered entirely homogeneous. Moreasphaltum is now run Into the groove, immediately or after the firstlayer has been allowed to cool to a semlliquid or solid consistency, andthe second layer, thus formed, is heated as the first. This operation isrepeated until the groove is full of asphaltum free from bubbles orother imperfections and entirely homogeneous throughout. Each joint istreated as described, whereupon the entire surface is coating whichgives perfect protection to the.

underlying wood, and the extra thickness at the joints eliminates thetrouble due to leaks commonly met with in tanks lined by the methodsheretofore in use.

As already stated, asphaltum is a very effective material for thelining, but It is to be understood that my method is not hmlted to theuse of asphaltum. For example, par aflin may be used, or any othersubstance which will sufliciently resist the chemical action of theparticular electrolyte which the tank is to contain. I

Having now fully described my invention, what I claim is:

1. The method of coating the interior of an electrolytic tank, whichconsists in flowing upon the inner surface of the tank asphaltumliquefied by heat; passing a flame over the layer of asphaltum thusformed, to expel bubbles or other imperfections therefrom; flowing asecond layer upon the first, and passing a flame over the same asdescribed; and repeating these steps until a coating of the desiredthickness is obtained; as set forth.

2. The method of coating the interior of an electrolytic tank composedof sections the.

joints between which are formed with grooves in the inner surface of thetank, which consists in depositing a layer of re sistant material in thegroove, treating the layer to'eradicate imperfections" therein and whichconsists in flowing into the grooves layers of resistant materialliquefied by heat; each layer being re-heated, in the groove, to expelbubblesor other imperfections, and repeating these steps until thecoating in the grooves is thick as desired; then flowing resistantmaterial over the entire inner surface of the tank; heating the layerthus formed to expel bubbles or other imperfections, repeatin thesesteps until the surface coating is thick as desired, as set forth.

4. The method of sealing the oints of an electrolytic tank composed ofsections, said joints being formed wlth grooves in the inner surface ofthe tank, which consists in flowing melted asphaltum into the groove toform a layer; passing a flame over the layer to heat the same andthereby expel bubbles or other imperfections therefrom; andrepeating'these steps as often as may be necessary to produce a depositof the desired thickness in the groove; as set forth. JOHN F. MILLER.

Witnesses: J. M. STRACHAN,

LEWIS MASSON.

